The CHDIM command lets you modify an existing dimensioning by entering the same dynamic dragging interaction that determines its dimension style, position layout and text annotation, as that provided in its original creation.
You will be asked to pick up the dimension to change by the prompt:
The rest operation depends on the type of the dimension entity you have picked up. See the related dimension commands that create various type of dimensioning for further informations on the operation.
The CHDIM command is an external command provided by the TCL program file "CHDIM.TCL" or "CHDIM.TCA". Either file must be present in the COMMANDS sub-directory where the TwinCAD resides. If you can not issue CHDIM command, you may solve the problem by copying the "CHDIM.TCL" to the COMMANDS sub-directory.